Stiffness and Damping of Sands in Torsion Shear

A laboratory investigation was carried out into stiffness and damping of sands as sheared in a torsional shear apparatus. In the drained monotonic and cyclic loading tests, a particular care was taken of the small strain measurements in which the secant stiffness was measured over a wide range of shear strain from about 10-6 to 10-2. Despite the marked differences in the grain size and the sample preparation method among the sands, a fairly good coincidence of the secant stiffness was seen, in common, in the range of shear strain less than about 1 x 10-5 between two types of tests using the monotonic and cyclic loadings. However, the response was softer in the monotonic loading tests for the larger strains. It has also been pointed out that the damping when examined in relation to the normalized secant shear modulus was scarcely affected by the confining pressure, and that the values of damping were smaller than those so far available in the literature

A Research on a New Science Curriculum Development Based on ‘Nature Of Science’ Ⅲ : Reconstruction of a Coherence Science Curriculum from Elementary School to Upper Secondary School

本研究は，新しい科学観を取り入れた小学校から高等学校までの理科カリキュラムを開発することを目的としており，今年度は３年次にあたる。これまでの成果と課題をもとに，初等・中等教育で一貫して「科学の本質」を学ぶためのフレームワーク構築に向け，小学校から高等学校を通じて系統的に取り扱うことが可能な内容について検討を行った。 中学校における実践からは，理科教師が，科学者コミュニティーによる知，政策決定者や教師たちによる教えるべき知，児童・生徒の発達段階や文脈などを考慮した教える知，について可能な限り熟知する必要があることが示唆された。また，論証活動を行う際の，教師の振る舞い方も重要であることも明らかとなった。 また，小学校における実践では，学年による差異はあるものの，見たことや考えたことの違いを次第に意識化させることによって，観察や実験等のレポートの書き方の指導にも繋がることが明らかとなった。 以上の実践より，科学の本質を初等・中等教育で一貫して教えるためには，これまでの実践の視点の変容に基づく教師による授業方略の在り方や投げ込み的教材を使用する教師の意図が，いかに重要であるかを示唆している。This study develops a new science curriculum for elementary to upper secondary schools which include the concept of the “Nature of Science”. We examined possible content to build a systematic framework for mentioned above science education. The practice at junior high school shows that teachers should be familiar with scholarly knowledge, knowledge to be taught by the policy makers and teachers, and taught knowledge which students understand through learning along with the students’ ages and contexts. The teacher’s behavior in argumentation by pupils is also important. The practice at elementary school shows that perceptions of the crucial distinction between inference and observation lead students to write good reports. These practices exemplify that teaching Nature of Science consistently to elementary and lower secondary students should largely depend on the teachers’ methods of instruction and what material they develop from a new viewpoint